This invention relates to a loading device of a disc player using light such as CD (Compact Disc) or DVD (Digital Video Disc).
Generally, the disc player comprises a loading motor for loading and unloading a tray unit mounted on one side of a main base and for capturing a disc, and a driving motor for a pick-up mounted on another side of the main base and the pick-up formed on a guide shaft of the pick-up base to slide. Further, the loading device comprises a rack part formed on one side of the tray unit and combines a pinion gear which receives the turning effect from the loading motor into the rack part, thereby a corresponding movement of the disc is executed to a turn table formed on the pick-up base, and loading and unloading of the tray unit is executed by these structures.
Hereinafter the structure and movement of the disc loading device are described in detail by accompanying FIG. 1 to FIG. 3.
FIG. 1 is a perspective view of a general disc player, FIG. 2 is a top view of the FIG. 1, and FIG. 3 is a front view.
As shown in the above FIGS, a conventional disc player includes a tray 13, and a loading motor 2 mounted on one side of a main base 1 mounted within a main body 20, in which the turning effect of the loading motor 2 delivered through a belt 3 to an idle gear 7 having a pinicn gear 7a via a first and second gears 5, 6, the above gears compose a gear train from a pulley 4.
Further, an arm 9 is rotatively mounted on a shaft of the second gear 6, whereby the idle gear 7 is rotatively mounted on another shaft 9a mounted in a first end part 9b, and a guide bush 10 is protected on a second end part 9c. Then a cam 11 having a cam groove 11a is rotatively mounted on a cylindrical outer peripheral surface at lower side of the shaft 8, and lower side of the guide bush 10, which is extended toward the bottom side through a bush introducing grooie 12 formed on the main base 1, is inserted into a bush inserting groove 11b.
On the other hand, a rack gear 14 mounted according to driving direction of the tray 13 at one side of bottom surface of the tray 13 and combined with the pinion gear 7a of the idle gear 7, where the rack gear 14 includes a linear rack gear 14a mounted according to driving direction of the tray 13, and a circular rack gear 14b.
A sign 15 represents a protection formed on a pick-up supporting part for supporting a pick-up base (not illustrated) and combined with the cam groove 11a of the cam 11, where the; pick-up base is fixed with hinge on the main base 1 and on which the pick-up is mounted.
Regarding the above-identified structure, a movement process of the tray of conventional disc player is described in the following.
Firstly, when a loading signal is applied to the apparatus in state that the tray 13 is shifted to the main body 20, in other words, a disc D is placed on the ejected tray 13, the pulley 4 mounted on the motor shaft clockwise turns in accordance with driving of the loading motor 2, and the turning effect of the pulley 4 is delivered to the first gear 5, the second gear 6 and idle gear 7, thereby the pinion gear 7a which combined with the rack gear 14 of the tray 13 moves to a loading position of the tray 13.
If the pinion gear 7a which receives turn affect from the loading motor 1 clockwise turns, the tray 13 having the rack gear 14 moves in the direction of the arrow in FIG. 2. The movement of the tray 13 is finished when a rear end part of the linear rack gear 14a reaches to the pinion gear 7a as shown in FIG. 2; thereafter the apparatus is continuously driven for a safe landing on the turn table (not illustrated), when the movement of the tray 13 is finished.
Further, if the pinion gear 7a turns without stop when the movement of the tray 13 is finished, the arm 9 counterclockwise turns centering around the shaft 8 by a turning of the pinion gear 7a of the idle gear 7 mounted on the first end part of the arm 9 which is rotatively mounted on the shaft 8 of the second gear 6, and the pinion gear 7a moves in accordance with the circular rack gear 14b. In this process, the guide bush 10 also turns in a counterclockwise direction according to the guide groove 12.
At this time, the cam 11 turns centering around the shaft 8 by that the end part of the guide bush 10 is combined with the bush inserting groove 11b formed on a side of the cam 11, thereby the projection 15 of the sled base which combined with lower part of a eject portion (a first portion) (11d) of the cam groove 11a is placed in a loading position (a second portion) (11c) of the cam groove (11a), then the disc placed on the tray 13 lands on the turn table of the spindle motor by a movement of the pick-up base.
An unloading movement of the disc is executed by reversing the above movements.
In the conventional loading device of the disc tray, since the loading motor is fixed on a side of the main base, there are many components for delivering the driving power from the loading motor to the pinion gear, turning radius of the idle gear is large, and the large belt pulley is used, it is impossible to minimize the size of the apparatus is and to increase the delivered power.
Although not shown in the drawings, the prior art also requires a rocking device for holding the tray; therefore, the miniaturization of the apparatus is difficult.